CN1792654B

CN1792654B - Vehicle tire

Info

Publication number: CN1792654B
Application number: CN2005101301577A
Authority: CN
Inventors: 白水利通
Original assignee: Sumitomo Rubber Industries Ltd
Current assignee: Sumitomo Rubber Industries Ltd
Priority date: 2004-12-24
Filing date: 2005-12-12
Publication date: 2010-05-05
Anticipated expiration: 2025-12-12
Also published as: EP1674293A3; US20060137789A1; JP2006176079A; EP1674293A2; CN1792654A; EP1674293B1; US7581574B2; JP4392339B2

Abstract

A pneumatic tire comprises a tread portion provided with annular regions each provided with axial grooves each extending from one of the axial edges of the annular region, wherein each axial groove is defined as having a groove width of from 2.0 to 6.0 mm and an axial length of not less than 40% of the axial width of the annular region. The annular regions are different from each other with respect to the number Nj of the axial grooves therein, and the greatest common divisor of the different numbers Nj of the grooved annular regions is in a range of from 10 to 40.

Description

Vehicle tyre

Technical field

The present invention relates to a kind of vehicle tyre, more particularly, relate to a kind of tread contour that can improve noise performance.

Background technology

The vehicle noise mainly is the combination of the mechanicalness noise that produces such as tire noise and driving engine, driving device.

In recent years, mechanicalness noise is significantly reduced.Particularly, under the situation of hybrid vehicle and storage battery car, when using electro-motor, mechanicalness noise is almost nil.In this case, press for tiremaker and produce the tire that produces less noise.

So far, know, almost always be to use so-called variable spacing method as the effective means that reduces tire noise as the technical personnel in tread design field.In the variable spacing method, the cycle minimizing along circumference repeats to arrange the tyre surface parts like this, can not produce significant peak value in the noise sound spectrum, in other words can be at characteristic frequency place rising sound pressure level.

On the other hand, Japanese Patent 2805472 (publication number: 63-159110) disclose a kind of tire, its tread portion is divided into the piece of a plurality of in-line arrangements along the circumferential direction, wherein, in order to reduce noise, the quantity of each axial groove in the ranks is different, and, the inboard quantity that is in piece the delegation that increases from the lateral of vehicle.

For the further tire noise that reduces, inventor's research is also found: even make tire according to variable spacing method or above-mentioned prior art, occur the synchronous of pulse sound generation possibly, this worsens noise more.Pulse sound is derived from groove or tyre surface parts, and these grooves or tyre surface parts axially are being in diverse location but in the position that upwards is in week much at one.For example, the what is called when the air in the groove sprays owing to the groove volume-variation, heard in the process of moving suction noise and the ground of when the axially extended edge of tyre surface parts (as piece) contacts with ground, being heard in the process of moving contact sound become as described in pulse sound.Say further even axial groove is a bevelled, when the noise that also is difficult to an axial groove of prediction reaches its maximum acoustic level.Like this, be difficult to determine whether to occur described synchronous by the ad-hoc location (as the end) of comparison groove.

Summary of the invention

Thereby, the inventor has carried out further research, to reduce or to avoid the synchronous of pulse sound generation and found a kind of method, even it is also very effective that this method is used separately, and draw can be used in combination with any variable spacing method or prior art the time with variable spacing method, test when it, this method will be more effective.

Therefore, an object of the present invention is to provide a kind of air-inflation tyre, its noise performance is able to effective raising.

According to the present invention, a kind of air-inflation tyre comprises: a tread portion, have the annular region of at least three troughs of belt on it, and the annular region of each trough of belt is provided with axial groove, each axial groove extends from one of them edge of the annular region of trough of belt, wherein:

Each axial groove is defined as: its groove width is 2.0 to 6.0mm, and axial length be not less than trough of belt annular region axial width 40%.

The annular region of at least three above-mentioned troughs of belt differs from one another according to the number N j that is arranged at axial groove therebetween, and,

The greatest common divisor that number N j is set of the axial groove in described at least three annular regions with groove is in 10 to 40 scopes, wherein

Described tread portion is provided with by along circumference M the tread contour that the decorative pattern unit forms, each decorative pattern unit is defined as on whole tread width and extends and include some axial grooves from the annular region of described at least three troughs of belt, and have between the annular region that number N j is set of different axial grooves, the number Tj that is provided with of the axial groove in the described decorative pattern unit in the annular region of each described trough of belt changes, and described quantity M equals described greatest common divisor.

In this application, term " groove width " expression perpendicular to this groove vertically or the line of centers of groove and the width that records.

Description of drawings

In conjunction with the accompanying drawings the specific embodiment of the present invention is described in detail now.

Fig. 1 shows the airtyred local plan view that launches according to tread contour of the present invention.

Fig. 2 shows the enlarged view of one of them motif unit.

The specific embodiment

In the present embodiment, vehicle according to the invention tire 1 is a kind of Pneumatic belt tire that is used for passenger vehicle.As well-known to those skilled in the art, air-inflation tyre comprises the bead part and a pair of sidewall part of extending of a tread portion, a pair of axially spaced-apart between tread edge and bead part.

Described tread portion 2 is provided with tread groove and the optional sipes per tire of establishing that limits tread contour.Fig. 1 shows an example of tread contour, and this tread contour is suitable for baby truck, and aims to provide low noise and control stability.

Tread groove comprises a plurality of main lines 3 that extend continuously along tire circumferential direction, thus, axially divides work at least three annular regions 4 tread portion 2.

Here, the main line 3 of circumferencial direction is the groove that a width is not less than 2.0mm, and its setting is used for draining.Therefore, width is not included in the described main line 3 less than the narrow groove of 2.0mm.And, groove width less than the part of 2.0mm not as the part of main line.

In the present embodiment, based on the purpose of draining and reduction noise, use straight flute as main line 3.But the zigzag groove that is made of linear portion or the zigzag groove of smooth curved can use too.But even if under the situation of zigzag groove, also preferred flexuose amplitude should be as much as possible little.

In this embodiment, four main lines 3 are arranged on the tread portion 2.Therefore, described tread portion 2 is made five annular regions 4 by dividing: along two the regional 4m and a central area 4c therebetween of axial outermost two regional 4e of tread edge Te, axial inner.

At least wherein two annular regions 4 (in this embodiment, be in five zones four---4m and 4e) are provided with axial groove 5 (hereinafter claiming " annular region of trough of belt ").

Among the present invention, also make the maximum effect that reduces the suction noise thus in order to get rid of groove very little to the suction noise effect or that do not have to influence at all, axial groove 5 is defined as: groove width Wg is 2.0 to 6.0mm, axial length F be not less than trough of belt annular region axial width Wr 40%.Thereby it is axial groove 5 that the groove of axial width outside above-mentioned scope is not considered as.And it is the part of axial groove 5 that the trench portions of groove width outside above-mentioned scope is not considered as yet.Even its groove width is in above-mentioned scope, it is axial groove 5 that axial length is shorter than that 40% groove or trench portions be not considered as yet.

And term " narrow groove " is meant groove or the sipes per tire of groove width less than 2mm.

Tread contour in the present embodiment is unidirectional decorative pattern, and it neither be point-symmetric neither the line symmetry.Half tread portion 2 that is positioned at tire equator Co one side be positioned at opposite side second half be provided with different decorative patterns.

To be positioned at half tread portion called after " outside tyre surface half Yo of " of vehicle outside, and be positioned at second half tread portion called after " inboard tyre surface half Yi of " of vehicle interior side, above-mentioned central annular region 4c tyre surface half Yi of biasing to the inside.Preferably, central annular region 4c is positioned at inboard tyre surface half Yi of fully.

As required, the outermost annular region 4e and the inner annular region 4m that are positioned at inboard tyre surface half Yi of are expressed as 4ei and 4mi with suffix " i ", and those parts in outside tyre surface half Yo of are expressed as 4eo and 4mo with suffix " o ".

In the annular region 4 of each trough of belt, each axial groove 5 all extends to another edge from an edge in this zone.

Axial groove 5 can extend through the whole width of annular region, still, in this embodiment, considers and will reduce noise, and in the qualification according to above-mentioned groove width restriction, axial groove 5 does not extend through the whole width of annular region.Yet, as described below, as if the narrow trench portions that includes outside above-mentioned scope, its extensible whole width that passes annular region.

Be furnished with axial groove 5ei in the axial outermost annular region 4ei of inboard, it tilts with the angle θ 1 that is no more than 15 degree with respect to the tire axle direction.Axial groove 5ei comprises: half-open axial groove 5ei1, its each all extend and end in the regional 4ei and have an osed top axial inner ends from the axial outer edge of regional 4ei; And, the axial groove 5ei2 that opens wide, it is parallel to half-open axial groove 5ei1 and extends and have and the half-open roughly the same length of axial groove 5ei1 from the axial outer edge of regional 4ei, and its each also be provided with a narrow extendible portion (narrow groove or sipes per tire) that extends to the axial inward flange of regional 4ei.

In the axial inner annular region 4mi of inboard, the axial groove 5mi2 that opens wide extends with the angle θ 2 greater than above-mentioned θ 1 from the axial outer edge of regional 4mi, and it is provided with a narrow extendible portion (narrow groove or sipes per tire) that extends to the axial inward flange of regional 4mi at the axial inner ends place.

In the axial outermost annular region 4eo in the outside, be furnished with respect to the tire axle direction to be no more than the angle θ 3 bevelled axial groove 5eo of 15 degree.Axial groove 5eo comprises: half-open axial groove 5eo1, its each all extend and end in the regional 4eo and have an osed top axial inner ends from the axial outer edge of regional 4eo; And, the axial groove 5eo2 that opens wide, it is parallel to half-open axial groove 5eo1 and extends and have and the half-open roughly the same length of axial groove 5eo1 from the axial outer edge of regional 4eo, and its each also be provided with a narrow extendible portion (narrow groove or sipes per tire) that extends to the axial inward flange of regional 4eo.Between axial groove 5eo, be furnished with the narrow groove 7eo substantially parallel with axial groove 5eo.

In the axial inner annular region 4mo in the outside, be provided with the narrow straight flute 8mo that circumferencial direction extends near its axial inside edge.And, in this regional 4mo, axially be furnished with angle θ 4 bevelled arc axial groove 5mo in the outside greater than angle θ 3 at narrow groove 8mo.Axial groove 5mo comprises: two kinds of half-open axial groove 5mo2, its axial outer edge from regional 4mo extends to the place near narrow groove 8mo, and, its each a narrow extendible portion (narrow groove or sipes per tire) that extends to narrow groove 8mo is all arranged at the axial inner ends place.Be furnished with the narrow groove 7mo of arc between axial groove 5mo, this narrow groove 7mo extends to the axial outer edge of regional 4mo from the axial inner ends of axial groove 5mo.

Central annular region 4c is not provided with axial groove 5.Yet in this embodiment, length is formed in the two edges of regional 4c less than 40% recess 9 dissected terrains of the axial width of regional 4c.

Therefore, in this embodiment, annular region 4c has formed the rib that extends continuously along tire circumferential direction, and remaining annular region 4ei, 4mi, 4mo and 4eo formed 4 rib-like tyre surface parts 6. here, and term " rib-like " is meant that the whole width of annular region is not that 2.0mm or the groove more than the 2.0mm cross by groove width.

For the axial groove 5 in the annular region 4 of each trough of belt number N j is set, have 2 kinds in the zone 4 at least, preferably have 3 kinds of different number N j that are provided with at least.

In this embodiment, the annular region 4ei of four troughs of belt, 4mi, 4mo and 4eo have three kinds of different number N jk (k is a suffix, is 1,2 and 3 among this embodiment) that are provided with.More particularly, the number that is provided with of the axial groove among the regional 4ei is Nj1, is Nj2 among the regional 4mi, and is Nj3 among regional 4mo and the 4eo.

According to the present invention, the greatest common divisor GCD that above-mentioned at least two kinds of differences are provided with number N j is being not less than 10, preferably is being not less than 12, also is not more than 40, preferably is not more than in 30 the scope.

As shown in Figure 1, tread contour is by forming along the circumference gap length PL that circumference repeats to arrange decorative pattern unit P and changes decorative pattern unit P according to predetermined order.In other words, (L≤M) individual decorative pattern unit P arranges around tire according to the determined order of one of variable spacing method (comprising existing method) will to have the M of the different circumference gap length PL of L.The purpose of using the variable spacing method is: wherein an edge covers another edge Te from tread edge is decorative pattern unit rather than independent tyre surface parts or groove.

Have between the annular region that difference is provided with number N j, the number Tj that is provided with of the axial groove 5 in each the decorative pattern unit P in each annular region changes.For example, among Fig. 2, the number Tj1 that is provided with among the regional 4ei is 4, and the number Tj2 that is provided with among the regional 4mi is 2, and the number Tj3 that is provided with among regional 4mo or the 4eo is 3.Like this, because the number of the axial groove that the designer must consider is quite little, can relatively easily avoid the synchronous of pulse sound generation.

Along with decorative pattern unit P repeats M time along tire, the number N j1 of above-mentioned axial groove, Nj2 and Nj3 add up to: Nj1=Tj1 * M; Nj2=Tj2 * M and Nj3=Tj3 * M.In this embodiment, because the greatest common divisor of Tj1, Tj2 and Tj3 is 1, the greatest common divisor of above-mentioned Nj1, Nj2 and Nj3 equals M.Thereby the tread contour among this embodiment forms by decorative pattern unit P is repeated GCD time (promptly 10 to 40 times) along circumference.

Like this, if the greatest common divisor that number Tj is set of axial groove is 1 in the annular region, no matter whether use the variable spacing method, tread contour all forms by decorative pattern unit P is repeated GCD time.

As explained above, be arranged on the number (being maximum suffix kmax) that difference on the annular region 4 of trough of belt is provided with number N jk (k be suffix number) and be at least 2, preferably be at least 3 in the present embodiment.Consider noise performance, particularly preferably, the number that difference is provided with number N jk equals the number (A) or the number (A-1) of the annular region 4 of trough of belt.Like this, in this embodiment, be preferably 4 or 3.Except present embodiment, preferably, the number (kmax) that difference is provided with number N jk mostly is 5 most, because how will make some annular regions 4 be difficult to keep its necessary rigidity again.

If greatest common divisor GCD less than 10, diminishes owing to repeat the number of times M of decorative pattern unit P, then be difficult to use the variable spacing method.If greatest common divisor GCD greater than 40, is difficult to keep its necessary rigidity for the zone of axial groove number Tj maximum.Like this, control stability and anti-irregular wear etc. and will be inclined to deterioration.

As explained above, preferably, the axial groove 5 on the annular region 4 of trough of belt comprises two kinds of grooves: unlimited axial groove---its two ends are opened wide in the opposite two ends of annular region; And, half-open axial groove---one end opens wide and the other end ends in this zone fully. and this is because the suction sound that axial groove that opens wide and half-open axial groove produce differs from one another on noise spectrum, and by arranging that on an annular region these two kinds of grooves can improve noise spectrum. thereby, in the axial outermost annular region 4ei of inboard, half-open axial groove 5ei1 and the axial groove 5ei2 that opens wide alternately arrange in the following order: half-open, open wide, half-open, open wide, repeat successively. in the axial outermost annular region 4eo in the outside, half-open axial groove 5eo1 and the axial groove 5eo2 that opens wide alternately arrange in the following order: half-open, half-open, open wide, repeat successively.

Preferably, the number of the half-open axial groove in each zone of outside tyre surface half Yo of accounts for axial groove, and that percentum and this percentum among inboard tyre surface half Yi of of number N j is set is big, this is to control stability and anti-irregular wear, the higher rigidity of more inboard tyre surface half Yi of the acquisition of expectation outside tyre surface half Yo of because consider.Like this, as mentioned above, described half-open axial groove and unlimited axial groove to be arranged among corresponding annular zone 4eo and the 4ei be different.

And based on same reason, the area ratio Lo of land portion (%) of preferred outside tyre surface half Yo of is greater than the area ratio Li of land portion (%) of inboard tyre surface half Yi of, and its difference (Lo%-Li%) is arranged in 5 to 15 the scope.Here, the area ratio L/S of land portion is the ratio of actual contact to earth area L and gross area S.If, then will being difficult to improvement less than 5, difference Lo-Li controls stability and anti-irregular wear etc.If difference Lo-Li is greater than 15, then draining will lack of equilibrium, and then wetland earth-catching property tendency worsens.Consider the earth-catching property of doing ground and wetland, more preferably, the area ratio Lo of land portion of outside tyre surface half Yo of is arranged in 65% to 75% scope, and the area ratio Li of land portion of inboard tyre surface half Yi of is arranged in 60% to 70% scope.

Contrast test:

The model that has except that tread contour with spline structure is that 215/60R16 (manufacture experimently by part modification tread contour as shown in Figure 1 with radial-ply tyre, and test its noise performance by the baby truck of wheel rim model 16 * 6.5JJ).

The parameter and the test result of tread contour are as shown in table 1.

The noise performance test:

Used Japanese 3000cc FF type baby truck, its four wheels installation testing tire (pressure is 230kpa), moving velocity be respectively 40,60,80 and the situation of 100km/h under measure the noise level at lorry front stall place when travelling on the straight-side tyre test route in asphalt.

Table 1

Tire	Comparative example 1	Example 1	Example 2
Tire	Comparative example 1	Example 1	Example 2	The area ratio Li of land portion of land portion area ratio Lo (%) (%)	68 68	73 63	68 68
The number in the zone of the number trough of belt of annular region	5 4	5 4	5 4		68 68	73 63	68 68
	5 4	5 4	5 4	The axial outermost regions 4eo in the 4mo outside, axial inner zone in the axial inner of the axial outermost regions 4ei inboard that number N j inboard is set of the axial groove zone 4mi central annular region 4c outside in each zone	116 58 0 58 58	116 58 0 87 87	110 60 0 90 90
Difference is provided with the number (kmax) of number N j	2	3	3		116 58 0 58 58	116 58 0 87 87	110 60 0 90 90

Tire	Comparative example 1	Example 1	Example 2
Tire	Comparative example 1	Example 1	Example 2	Greatest common divisor GCD	58	29	10
Decorative pattern unit multiplicity M different spacing length PL number is provided with the annular region number that opens wide axial groove and half-open axial groove	58 5 4	58 5 4	20 5 4	Greatest common divisor GCD	58	29	10
	58 5 4	58 5 4	20 5 4	Noise performance (dB) 40km/h 60km/h 80km/h 100km/h	52.9 56.7 61.3 66.0	51.3 55.1 59.8 65.2	51.6 55.7 60.4 65.7

Claims

1. air-inflation tyre, it comprises:

Tread portion which is provided with the annular region of at least three troughs of belt, and the annular region of each trough of belt is provided with axial groove, and each axial groove all extends from one of them axial edge of the annular region of trough of belt, wherein,

Each described axial groove is defined as: groove width is 2.0 millimeters to 6.0 millimeters, and its axial length be not less than trough of belt annular region axial width 40%,

The number N j that is provided with of the axial groove in the annular region of described at least three troughs of belt differs from one another, and

The greatest common divisor that number N j is set of the axial groove in the annular region of described at least three troughs of belt is in 10 to 40 scopes, wherein

Described tread portion is provided with by along circumference M the tread contour that the decorative pattern unit forms,

Each decorative pattern unit is defined as on whole tread width and extends and include some axial grooves from the annular region of described at least three troughs of belt, and

Between the annular region of the trough of belt that number N j is set with different axial grooves, the number Tj that is provided with of the axial groove in the described decorative pattern unit in the annular region of each described trough of belt changes, and

Described quantity M equals described greatest common divisor.

2. air-inflation tyre as claimed in claim 1, wherein,

The annular region of described at least three troughs of belt is the annular region of four troughs of belt.

3. air-inflation tyre as claimed in claim 1, wherein,

The annular region of described at least three troughs of belt is the annular region of five troughs of belt.

4. as claim 1,2 or 3 described air-inflation tyres, wherein,

Described tread portion further is provided with central annular region, and described central annular region is not provided with axial groove, and has formed the rib that extends continuously along tire circumferential direction.

5. as claim 1,2 or 3 described air-inflation tyres, wherein,

Described tread portion further is provided with an annular region with trough of belt of axial groove, its axial groove be provided with number N j equal described at least three troughs of belt annular region one of them number N j is set.

6. air-inflation tyre as claimed in claim 1, wherein,

The described axial groove that is arranged on the annular region of one of them described trough of belt comprises unlimited axial groove and half-open axial groove, wherein said unlimited axial groove extends and is provided with the narrow extendible portion of the axial inward flange of an annular region that extends to described trough of belt from the axial outer edge of the annular region of trough of belt, and described half-open axial groove extends and ends in the annular region of described trough of belt from the axial outer edge of the annular region of described trough of belt.

7. air-inflation tyre as claimed in claim 1, wherein,

The area ratio Lo of land portion of outside tyre surface half one is greater than the area ratio Li of land portion of inboard tyre surface half one, wherein said outside tyre surface half one is meant half tread portion that is positioned at tire equator one side, described inboard tyre surface half one is meant second half tread portion that is positioned at the tire equator opposite side, and when the area ratio Li of land portion of the land area ratio Lo of described outside tyre surface half one and described inboard tyre surface half one recently represents with percentage, difference (Lo%-Li%) between the area ratio Li of land portion of the land area ratio Lo of described outside tyre surface half one and described inboard tyre surface half one is in 5% to 15% scope

Wherein, when with mounting of tyre on vehicle the time, tyre surface half one in the described outside is placed on the outside of vehicle, and correspondingly, described inboard tyre surface half one is placed on the inboard of vehicle.